In -Eonly mode, pragmas are not correctly recognized

[jsonn]

Bugzilla Link	9537
Resolution	FIXED
Resolved on	Dec 04, 2013 04:22
Version	trunk
OS	Linux
CC	@llunak

Extended Description

Create a file containing only:

_Pragma("GCC visibility push(default)")

and compile with "clang -MM test.c -Wall". Observe warnings about unknown pragma.

[llvmbot]

Have the same problem when using -M flag to generate dependencies:

$ clang -I. -I../include -Wall -fno-strict-aliasing -Wstrict-prototypes -Werror -D_GNU_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -g -O0 -DDEBUG -I/usr/include/libxml2 -fPIC -fvisibility=hidden -M uuid.c delta_read.c delta_sysfs.c balloon_util.c fsck_util.c ploop.c xml.c logger.c balloon.c lock.c fsutils.c gpt.c crc32.c merge.c util.c pcopy.c di.c cleanup.c > .depend
In file included from uuid.c:28:
In file included from ./ploop.h:11:
../include/libploop.h:21:13: error: unknown pragma ignored [-Werror,-Wunknown-pragmas]
#pragma GCC visibility push(default)
^
../include/libploop.h:238:13: error: unknown pragma ignored [-Werror,-Wunknown-pragmas]
#pragma GCC visibility pop
^
2 errors generated.

$ clang --version
clang version 3.0 (tags/RELEASE_30/final)
Target: x86_64-redhat-linux-gnu
Thread model: posix

[llvmbot]

TO REPRODUCE:

cat << EOF > test.h
#pragma GCC visibility push(default)
#pragma GCC visibility pop
EOF

clang -Wall -M a.h

ACTUAL RESULT:

a.h:1:13: warning: unknown pragma ignored [-Wunknown-pragmas]
#pragma GCC visibility push(default)
^
a.h:2:13: warning: unknown pragma ignored [-Wunknown-pragmas]
#pragma GCC visibility pop
^
a.o: a.h
2 warnings generated.

EXPECTED RESULT:

No warnings

[llvmbot]

For the reference, gcc 4.7.0 gives no warnings:

gcc -Wall -M a.h
a.o: a.h

[llunak]

r196372